Humans can't live without blood. Without blood, the body's organs couldn't get the oxygen and nutrients they need to survive, we couldn't keep warm or cool off, fight infections, or get rid of our own waste products. Without enough blood, we'd weaken and die.
Here are the basics about the mysterious, life-sustaining fluid called blood.
Two types of blood vessels carry blood throughout our bodies:
1. Arteries carry oxygenated blood (blood that has received oxygen from the lungs) from the heart to the rest of the body.
2. Blood then travels through veins back to the heart and lungs, where it receives more oxygen.
As the heart beats, you can feel blood traveling through the body at pulse points — like the neck and the wrist — where large, blood-filled arteries run close to the surface of the skin.
The blood that flows through this network of veins and arteries is ...view middle of the document...
Blood also carries hormones released by the endocrine glands and carries them to the body parts that need them.Blood also carries carbon dioxide and other waste materials to the lungs, kidneys, and digestive system to be removed from the body.
When someone donates blood, the whole blood can be separated into its different parts to be used in this way.
Red Blood Cells: Red blood cells (also called erythrocytes) are shaped like slightly indented, flattened disks. RBCs contain the iron-rich protein hemoglobin. Blood gets its bright red color when hemoglobin picks up oxygen in the lungs. As the blood travels through the body, the hemoglobin releases oxygen to the tissues.
The body contains more RBCs than any other type of cell, and each has a life span of about 4 months. 2.4 million new erythrocytes are produced per second. Each day, the body produces new RBCs to replace those that die or are lost from the body.
The cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 20 seconds. Approximately a quarter of the cells in the human body are red blood cells. Diseases of Red Blood Cells: The most common condition affecting RBCs is anemia, a lower-than-normal number of red cells in the blood. Anemia is accompanied by a decrease in the amount of hemoglobin.
Iron deficiency anemia Lead poisoning Anemia due to chronic disease. Anemia due to kidney disease Sickle cell anemia